Mobile telephonic devices (“cell-phones”) capable of wireless communications are increasingly commonplace. Cell-phones typically integrate a variety of functionality into a single device, but the ability to carry out voice telecommunications remains central to the devices' purpose. Nokia of Keilalandentie 2-4, Finland and Motorola Inc. of Schaumburg, Ill., U.S.A. are two examples of manufacturers of such cell-phones, and each offer a variety of products in this category.
A typical cell-phone contains a communications interface for establishing wireless communications with telephony networks (“wireless networks”). In addition, a typical cell-phone also has a microcomputer which controls most of the functionality of the cell-phone and aids in processing of information that the cell-phone is presented with.
As part of its functionality, a cell-phone is called upon to establish communications with the wireless networks by accessing different network base stations as the user of the cell-phone roams through different geographic regions served by these base stations. Accordingly, a cell-phone is able to establish communications with other communications devices through the wireless network, allowing the cell-phone to place calls to and to receive calls from these other devices.
As the volume of communications in wireless networks grows, so does the volume of unwanted and unsolicited communications. These communications usually originate from mass marketing sources, but can be from other entities as well. Unwanted calls, in addition to being inconvenient, can be costly as well. For example, long distance marketing calls, which due to the cost structure of Voice over IP have now become more feasible, are costly since, typically, cell-phone owners pay long distance charges for long distance calls received as well as placed.
There has been at least one attempt to devise a scheme for blocking unwanted calls. Specifically, an internet marketing brochure (http://www.hackcanada.com/canadian/phreaking/bcpsl.html) discloses a call blocking service allowing the called party to divert up to twelve telephone numbers of their choice to a special recording that tells callers that the party they have reached has chosen not to take their call at this time. Numbers on the list can be altered by the subscriber at any time. This attempt, however, has several limitations. First of all, each subscriber's blocking list must be manually updated by each subscriber individually. Moreover, only a small number of calling numbers can be blocked. Finally, the call is diverted to a voice mail, which verifies the existence of that phone number to the caller. Bypassing this scheme, therefore, is relatively straightforward: if the initial attempt at placing an unwanted call is frustrated, the unwanted caller simply has to repeat the call using a new originating number. Given the limited number of phone numbers that can be blocked, and the manual nature of updating these by each subscriber, after several attempts, the caller is likely to reach most of the subscribers using this service. Moreover, according to this scheme, the caller's initial efforts are not altogether fruitless since even the diverted calls serve to verify the existence of a subscriber's phone number because of the voice mail.